21232249 has 2 divisors, whose sum is σ = 21232250. Its totient is φ = 21232248.

The previous prime is 21232247. The next prime is 21232259. The reversal of 21232249 is 94223212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18318400 + 2913849 = 4280^2 + 1707^2 .

It is a cyclic number.

It is not a de Polignac number, because 21232249 - 2¹ = 21232247 is a prime.

Together with 21232247, it forms a pair of twin primes.

It is equal to p_1343671 and since 21232249 and 1343671 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21232247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10616124 + 10616125.

It is an arithmetic number, because the mean of its divisors is an integer number (10616125).

Almost surely, 2^21232249 is an apocalyptic number.

It is an amenable number.

21232249 is a deficient number, since it is larger than the sum of its proper divisors (1).

21232249 is an equidigital number, since it uses as much as digits as its factorization.

21232249 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 25.

The square root of 21232249 is about 4607.8464601156. The cubic root of 21232249 is about 276.9057662751.

The spelling of 21232249 in words is "twenty-one million, two hundred thirty-two thousand, two hundred forty-nine".